National Geographic Friday the 13th Feature Quotes Prof. Woody Dudley

August 13, 2010

Underwood Dudley 2009.jpg August 13, 2010, Greencastle, Ind. — A National Geographic story today marking Friday the 13th includes comments from Underwood "Woody" Dudley, professor emeritus of mathematics at DePauw University. "You can't have any [years] with none, and you can't have any with four, because of our funny calendar," Dr. Dudley tells the publication.

The article by John Roach begins, "They date back to at least ancient Roman times, but Friday the 13th superstitions won't be getting much of a workout this year. Luckily for triskaidekaphobia sufferers, today is 2010's only Friday the 13th. That must come as a relief, after 2009's nine Friday the 13ths -- the maximum possible in a year," he notes.

The Gregorian calendar leads to "an ordering of days and dates that repeats itself every 400 years, Dudley noted. As time marches through the order, some years appear with three Friday the 13ths. Other years have two or, like 2010, one ... When the 400-year order is laid out, another revelation occurs: The 13th falls on Friday more often than any other day of the week. 'It's just a funny coincidence,' Dudley said."

Later, Roach states, "DePauw University's Dudley said nobody really knows why Friday the 13th has spawned so many superstitions. 'You've got to have something that is unlucky, and somehow they hit on 13,' he said. 'But all these explanations are just moonshine.'"